85 engine electrical.pdf - Vintage Snow

cBarometricPressure Sensor (BPS)The barometric pressure sensor is located inside theECU. Its function is to read atmospheric pressure.This information is then used by the ECU to determinefuel/air ratio, depending on pressure changes during agiven day, or for any altitude change. The barometricpressure sensor is an integral part of the ECU andcannot be replaced separately.No service can be performed on the barometricpressure sensor. However, the barometric sensorreading can be checked with the select monitor. Themonitor reads in millimeters of mercury. To get airpressure in inches of mercury, divide this number by25.4. Compare the reading to an accurate barometer.NOTE: Readings reported by the radio or televisionare corrected to sea level. The select monitor is anactual reading. Any changes to the stock machinewhich affect the air pressure around the ECU willcause the barometric sensor reading to be inaccurate.CHIPPRESSURESENSORENGINE ELECTRICALSystem III - ElectronicsSelect Monitor ReadingsModeFOgDescriptionBarometric SensorNormal ReadingBarometric Pressure in Millimeters ofMercury4.578/94